What Changed Between NAIC Auto Insurance Data Releases?
A computed release archive, change feed, and prior-release downloads built from five retained annual state-level records.
Research
Original data research from PlainInsurer, drawn directly from the current dataset; every figure is auditable to its source record.
What can you learn from PlainInsurer research?
What this research covers
PlainInsurer research ranks registry and public-file insurance records across 215 companies in 51 jurisdictions (2024-2026), including 216 CMS denial-rate rows from 145 reporting issuers.
- 215
- companies in the mirror
- 51
- states & DC covered
- 216
- CMS denial-rate rows
Briefs below answer complaint-index, market-share, denial-rate, or premium-change questions from the live NAIC/CMS mirror; they are registry statistics, not coverage advice.
Top 10 US Insurers by NAIC-Recorded Complaint Index Composite
NAIC complaint-index, denial-rate, and prior-authorization composite score across 215 US insurance companies.
Largest Auto Insurance Companies in the US, Ranked by Market Share
The biggest US auto insurers ranked by NAIC-reported market share across the 25 largest carriers.
Top 10 US Insurers by CMS-Reported Claim Denial Rate
CMS Transparency in Coverage claim-denial rate across 200+ insurer-state combinations.
Largest Home Insurance Companies in the US, Ranked by Market Share
The biggest US homeowners insurers ranked by NAIC-reported market share across the 125 largest carriers.
Largest Life Insurance Companies in the US, Ranked by Market Share
The biggest US life insurers ranked by NAIC-reported individual-life market share across the 125 largest carriers.
Largest Health Insurance Companies in the US, Ranked by Market Share
The biggest US health insurers ranked by NAIC-reported accident-and-health market share across the 125 largest carriers.
Largest Insurance Companies in the US: Market Leaders by Line
A source-checked market map of the largest auto, home, life, and health insurance groups without claiming an unsupported cross-line total.
Auto Insurance Premium Changes by State, 2022 to 2023
A 51-jurisdiction, NAIC-derived change report that separates dollar and percentage movement in reported average auto insurance expenditure.
Auto Insurance Rate Changes by State, 2019-2023 (5-Year Trend)
The full five-year retained NAIC series, ranked by percentage and dollar change - the longer trend behind the latest annual move.
Download the extracts behind these research briefs: complaint-index.csv, marketplace-denial-rates.csv, and auto-insurance-rates.csv.